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Stargazing Telescope adventures

  1. Aug 1, 2010 #1

    Chronos

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    I recently acquired a Meade LXD75 SN10 telescope [Schmidt-Newtonian]. It has been an adventure. It is big, heavy, awkward, etc. I only have to lug the beast about 15' to set it up, so despite my age and feebleness I can manage the task in about 15 minutes. I thus far have made the following observations:

    1] one of the clamp rings does not align with the mounting ring.

    2] the threaded end of the T-handle [part that secures mount to tripod] is bent. Very weird.

    3] the stock eyepiece and barrel are mismatched. I 'lost' the lens half of the eyepiece about a dozen times before it occured to me there might be a problem [doh!].

    4] After 4 attempts, I still 'goto' bed before getting within 10 degrees of target using the the 'goto' function.

    I returned the clamp ring and T-bar for replacement [shipped, of course, at my expense]. I stole a barrel from an ancient eyepiece. It fit perfectly. The 'goto' aint even close thing is a head slapper. I 'trained' the drive until it will fetch, roll over and beg for biscuits, but, still have some skull density room to work with. The bent T-bar may have something to do with that. And to think, I nearly forgot the joys of backyard astronomy.
     
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  3. Aug 1, 2010 #2

    russ_watters

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    Sorry to hear that.
    Almost sounds like damage at the factory, durinig shipping or by a previous user. My telescope mount was used and damaged when I bought it (it is an Orion, not a Meade) and the factory acknowledged that it "accidentally" sent me a returned unit after I pointed out the evience (scratches on the mounting plate, indicating someone had not very carefully mounted a scope on it before). I don't remember if I paid the shipping to return it, but I'm thinking no.
    Not sure what you mean - are you saying that the tube diameters are vastly different? If so, you should send the eyepieces back - or just send the whole thing back - because they aren't the eyepieces that were supposed to come with it. Standard eyepieces are 1.25". Crapy K-Mart specials often come with 0.96" eyepieces.
    Goto can be tricky if you're not used to it. You need to follow the instructions exactly and they aren't always clear. A few things to look for/common mistakes:

    1. Make sure your latitude is entered properly. People often swap east and west.
    2. Daylight savings time!
    3. Make sure you are accurately physically aligning the polar axis.
    4. Make sure you have the right star centered when doing it's alignment procedure.
    5. Make sure your clutches are clamped-down (so you can't move the scope just by pushing on it).

    How far is your first alignment star from your field of view when running the computer's alignment routine? If it isn't within a couple of degrees, then something in your setup is wrong. An alignment 10 degrees off should be a "fail" by the computer: it shouldn't even allow you to continue without re-aligning.
     
  4. Aug 1, 2010 #3
    This is what happens to in-experienced users who jump into astronomy too quickly.

    As russ said, you must accurately polar allign the mount for your go-to system to work. If you live in the northern hemisphere, this is fairly trivial if you know the sky well enough to find Polaris. If you live in the southern hemisphere, it can be much more difficult.

    As for the eyepieces, they come in 1.25" and 2" barrel diameters. There should be an adapter on the focuser, you simply remove it for 2" and thread it (or clamp it back with set screws, whichever your focuser uses) back on for the 1.25" ep's.

    People often buy computerized scopes thinking they will do the work for them, but usually they end up being more work than a normal telescope. I'd recommend learning the sky a bit before you try to get into this fancy equipment, maybe go to some star parties and see how other people's gear is set up properly.
     
  5. Aug 1, 2010 #4

    russ_watters

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    I disagree. This is [probably - unless the telescope is broken, which is a real possiblity here] what happens when someone is new to a pursuit. It doesn't have anything to do with "jumping in too quickly".
     
  6. Aug 1, 2010 #5
    Many people spend lots of money on scopes without having any idea how they work - get frustrated and end up never using them. That grief could be saved by starting off with a cheap dobson or going and seeing telescopes and talking to people with experience.
     
  7. Aug 1, 2010 #6

    russ_watters

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    Starting off with a cheap Dobsonian isn't going to give someone any insight into how to make a goto scope goto, nor would I assume that this is Chronos's first telescope.
     
  8. Aug 1, 2010 #7

    chemisttree

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    Chronos, did you get that scope at Wal-Mart online? There has been much discussion about the Meade SN's being very screwed up from Wal-Mart.

    I find that the CG-5 AGST mount I have is a real dog for goto. The motor for the dec axis has a plastic housing which rubs the mount and screws up the dec positioning. I'm contemplating removing the plastic housing, warming it with a heat gun and pushing it back into shape and then cooling it in a tub of cold water while holding the new shape.

    I'm back to using my Atlas for everything... even my 66 mm and 80 mm apos. That's a lot of mass to move around for those weekly outreach events.

    When my goto goes off, I find that slipping the clutches and manually positioning the first alignment star will get you back into the ballpark. Just loosen the clutches and get the first star close. Finish the alignment on the first star with the paddle and continue as usual. This corrects all problems like wrong lat/long, date, time.

    Good luck with it.
     
  9. Aug 2, 2010 #8

    Chronos

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    Hehe, not from Walmart, ordered from Meade dealer. Not my first time with a scope, although goto had not been invented the last time I bought one, so, I am a goto virgin. The procedure seems pretty straightforward, align scope to celestial north [I know I'm within half a degree] and select arcturus as the first alignment star. The scope slews to where it believes arcturus is, but, misses badly. I use the autostar to center it. The next alignment star is Deneb. It also misses badly, and I again center using autostar. Autostar claims the scope is now aligned. As a humor check I select arcturus again off the goto menu. It misses badly. That manual centering things sounds promising. Gonna give that a try.

    The eyepiece [Meade 4000 super plossl] barrel is oversized just enough that the threads dont get a good grip. I dont know how you can mess that up, but, it is what it is. I have other eyepieces barrels, so it was mainly a nuisance.
     
  10. Aug 2, 2010 #9

    russ_watters

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    You may want to consider calling tech support, having them run you through it, then sending it back if they can't help. It's possible you got a lemon.
     
  11. Aug 3, 2010 #10

    Chronos

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    Just warts and ignorance, IMO. The optics are outstanding and the drive appears to be reasonably well constructed [ I disassembled it]. I'm a mechanical engineer so I am unreasonbly confident in my judgement. I'm going to regrease the whole thing though - the stock grease is awful. Going to flush it all out and regrease with a synthetic. Also need a little more clearance in the plastic motor housings, they appear to rub in certain positions. A few washers should fix that.
     
  12. Aug 3, 2010 #11

    collinsmark

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    Hello Chronos,

    I'm assuming your LXD75 SN10 is on an equatorial mount?

    If the Autostar's alignment is missing really, really badly, it could be because the Autostar is operating in Alt-Az mode. Make sure it is set configured for equatorial mode if you are using an equatorial mount.

    If your Autostar is like the Autostar II (I'm familiar with the Autostar II, but not so much with Autostar), if it is in equatorial mode, and if you're in the Northern hemisphere, it will slew to Polaris as the first alignment star and instruct you to adjust your mount's azimuth and altitude controls (not declination and right ascension [i.e. not using your Autostar controls]) for Polaris only.

    But if it's not instructing you to make any manual adjustments on your mount (azimuth and altitude) for Polaris, it might think you're using an Al-Azimuth mount. There should be setting you change in the setup menu.
     
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